Opening up the sample containers

In the experiment carriers, some of the samples were exposed to an inert gas atmosphere, while others were exposed to vacuum conditions. Some of the carriers, each of which contained ten million spores, were exposed to ultraviolet radiation through eight-millimetre-thick highly ultraviolet-transparent glass. Other samples received a reduced radiation dose through optical filter wheels. The microorganisms placed on the lower two of the three stacked trays remained completely protected from extraterrestrial UV radiation. The researchers also simulated different scenarios with the meterorite dust – some microorganisms were covered with it, while others were mixed together with it.